I usually share IPs with police when they request it. Have police (any police, worldwide) contact me and if it seems like they have reasonable probable cause, I'll give them the IPs in question. I don't give IPs to random people because that just encourages witch hunts and vigilante justice.

Yakov (or whatever his name) made a mistake on his server and I could use it to trace his server's real IP add although he stayed behind cloudfare.The ISP is Cherry Servers, UAB with the below contact. This company accept BTC for renting dedicated server and I think Yakov used BTC to pay; this was a smart move because he just needed to provide his email address => this prove that he's a really scammer, he intended to scam all people right from the start.